iOS UIDatePicker NSDateFormatter

UIDatePicker *picker = [[UIDatePicker alloc] init];

/*

UIDatePickerModeTime,           // Displays hour, minute, and optionally AM/PM designation depending on the locale setting (e.g. 6 | 53 | PM)
    UIDatePickerModeDate,           // Displays month, day, and year depending on the locale setting (e.g. November | 15 | 2007)
    UIDatePickerModeDateAndTime,    // Displays date, hour, minute, and optionally AM/PM designation depending on the locale setting (e.g. Wed Nov 15 | 6 | 53 | PM)
    UIDatePickerModeCountDownTimer

*/

picker.datePickerMode = UIDatePickerModeTime; //时间模式

picker.locale = [[NSLocale alloc] initWithLocaleIdentifier:@"zh_CN"];

[picker addTarget:self action:@selector(dateChange:) forControlEvents:UIControlEventValueChanged];

//设置text的输入源
    self.mytext.inputView = picker;

// 设置text弹出的输入源上的工具view
    self.mytext.inputAccessoryView = [UIButton buttonWithType:UIButtonTypeContactAdd];//[btn addTarget]

- (IBAction)dateChange:(UIDatePicker *)sender
{
    NSDate *date = sender.date;
    NSDateFormatter *format = [[NSDateFormatter alloc] init];
    format.dateFormat = @"yyyy/MM/dd a HH:mm:ss";
    self.mytext.text = [format stringFromDate:date];
    NSLog(@"--dateChange--");
}